(At around one hour and twenty-two minutes) When Draco Malfoy says "I didn't know you could read" to Harry (looking like Goyle with polyjuice potion) it was actually improvised, because Tom Felton forgot his line.

It was Jason Isaacs' idea to have Lucius Malfoy sport long blond hair, as well as carry a walking stick, inside of which he would conceal his wand. He grew attached to the walking stick, and at one point tried to walk off with it, though he was caught.

Daniel Radcliffe was initially only offered £125,000 (approximately $181,500) for this film. The actors' union Equity stepped in and negotiated new terms, which increased his salary to roughly £2 million ($3 million).

During production, Emma Watson frequently brought her pet hamster Millie on set. Unfortunately, Millie passed away shortly after shooting began. The set department created a specially-made hamster coffin, complete with velvet lining, and the name "Millie" engraved on the top. "I don't think a hamster has ever had a better send-off", Watson said.

Rupert Grint has such a severe case of arachnophobia, he has still not watched the entire scene where Ron and Harry are in Aragog's hollow. In that scene, Ron's frightened look, and his uncomfortable squirming throughout, was not from acting, but from Rupert being legitimately terrified at even the thought of spiders.

The Weasleys' car is a Ford Anglia. This is the same color and model car that J.K. Rowling, and her best friend from school, used to ride around in when they were younger. She used the car for the book, and later the movie, out of her fond memories of driving in it.

Shirley Henderson, who played Moaning Myrtle, is the oldest actress (age thirty-seven) to portray a Hogwarts student.

(At around fifteen minutes) The opal necklace, which plays an important role in Harry Potter and the Half-Blood Prince (2009), can briefly be glimpsed inside a display case in Borgin and Burkes' shop in Knockturn Alley when Harry first enters.

(At around seventeen minutes) When Hagrid (Robbie Coltrane) is escorting Harry (Daniel Radcliffe) out of Knockturn Alley, and again when Lockhart (Sir Kenneth Branagh) turns to show his other profile to the photographer, hardcover editions of Harry Potter books can be seen on the shelves.

The animatronic phoenix used to portray Fawkes looked so life-like (despite the fact that phoenixes are mythical creatures) that Richard Harris (Professor Albus Dumbledore) thought it was a real living bird when he first saw it.

Richard Harris (Professor Albus Dumbledore) died a few weeks before this movie's release.

Director Chris Columbus instructed cinematographer Roger Pratt to bring a darker look to the movie, reflecting the darker tone of the story. Hence, the sets were lit with more subdued lighting, and the color palette was desaturated a bit. These changes would continue throughout the franchise, with each movie getting darker and increasingly desaturated.

According to J.K. Rowling, Moaning Myrtle was a member of Ravenclaw House.

(At around twenty minutes) A gag from the book is rendered incomprehensible in this movie due to a lack of information. While chatting with the Grangers at the bookshop, Mr. Weasley says "I understand that other Muggles are afraid of you." This is because they are dentists.

Full-size models replaced the cast members in scenes where their characters have been petrified.

Although based on the second shortest book, this is the longest of the movies. Harry Potter and the Order of the Phoenix (2007), which is based on the longest book, is the second shortest of the movies.

Fourteen Ford Anglias were destroyed to create the scene where Harry and Ron crash into the Whomping Willow.

Lucius Malfoy originally was not supposed to have long hair. However, when Jason Isaacs was cast in the role, he requested the longer hair so that he could be distinguished from his son Draco. In order to keep the hair from falling in front of his face, Isaacs had to keep his head tilted back, which further added to the snobbishness of the character, as it made him appear as if he was "looking down his nose at everyone."

(At around two hours and twenty minutes) The "Let's just hope Mr. Potter will always be around to save the day" dialogue was improvised by Daniel Radcliffe and Jason Isaacs.

Young Hagrid was played by Martin Bayfield, who stands in for Robbie Coltrane as his height double in all of the Potter movies. His voice was dubbed by Coltrane for the sake of consistency.

(At around one hour and sixteen minutes) When Hagrid charges into Dumbledore's office to defend Harry, he is carrying a dead rooster in his hands. This is in reference to a scene in the book (cut from the movie) where Hagrid finds all of the roosters dead. The sound of a cock-crow is fatal to a basilisk.

Filming began three days after the release of Harry Potter and the Sorcerer's/Philosopher's Stone (2001). This makes this the only movie in the franchise that was produced and released within one year after its predecessor. Although Harry Potter and the Deathly Hallows: Part 1 (2010) and Harry Potter and the Deathly Hallows: Part 2 (2011) were released six months apart, they were filmed simultaneously.

(At around two hours and twenty-five minutes) Daniel Radcliffe was required to shave his leg for the scene where Harry reveals he's missing a sock.

In the U.K., this became the first movie to achieve a million DVD sales in its first weekend.

(At around two hours and twenty-five minutes) The script originally said that Hermione would hug Harry and Ron in the final scene. As the eleven-year-old Emma Watson was embarrassed about having to hug the boys in front of the entire cast, Chris Columbus allowed her to change the scene so that Hermione just hugs Harry, then starts to hug Ron, but the two get embarrassed and resolve by only shaking hands. Watson also stated in a recent interview that she kept letting Daniel Radcliffe go too quickly, so the movie was "frozen" for a few seconds to make the hug look like it lasted longer than it actually did. Her hesitation with Ron is also taken by fans as a precursor to the relationship that will develop between the two characters.

Nurses were drafted into the production when an outbreak of head lice occurred amongst the young cast.

Christian Coulson landed the role as Tom Riddle, even though he was twenty-three and exceeded the fifteen to seventeen age group set for auditions.

Many people think that Professor Gilderoy Lockhart is a character based on J.K. Rowling's ex-husband. Rowling has said, on her official website, that Lockhart is based in an egocentric person that she really dislikes, but he is not her ex-husband.

Hugh Grant was originally cast as Gilderoy Lockhart, but was forced to withdraw at the last moment because of scheduling conflicts.

(At around two hours and twenty-five minutes) When Lucius Malfoy tries to curse Harry at the end, he mutters "Avada..." As mentioned in the fourth book, this is the beginning of an Unforgivable Curse named "Avada Kedavra", or the killing curse. This rather makes it look like Malfoy is stupid enough to actually try to kill a child in the middle of a school, chock full of students and teachers, with no means of escaping. But as Jason Isaacs has explained in several interviews, the novel mentioned no specific spell for him to use and, since he had just been reading the fourth book at the time, this was the only curse he could remember. So, as it turns out, Dobby saved Harry's life in this scene.

Zoë Wanamaker didn't appear in this movie as Hogwarts' flying instructor, Madam Hooch, as Wanamaker found the salary unsatisfying. Her character was written out by giving Hooch's speaking lines to Professor McGonagall (Dame Maggie Smith) and other characters.

Eddie Redmayne, who was cast as Newt Scamander in Fantastic Beasts and Where to Find Them (2016), auditioned for the role of Tom Riddle.

The set for Dumbledore's office was, at the time of its construction, the most expensive set built for the movies. Chris Columbus and production designer Stuart Craig agreed that, as headmaster, Dumbledore should have the most elaborate office possible. However, they were informed that the proposed design, with its massive stone columns, bookcases, curio cabinets, paintings on the walls, tables filled with various objects, antique desk, throne-like chair, and a giant telescope, would be far too expensive to produce. The producers ultimately were able to secure the funds needed to build the set.

During post-production, producer David Heyman went to visit Richard Harris in the hospital. Though he was very weak from his illness, Harris insisted that the role of Dumbledore not be re-cast. Sadly, Harris passed away shortly before production was to begin on the next movie, necessitating a re-cast.

(At around fifty-five minutes) During the Quidditch Match, some of the music used while Harry and Draco chase the Golden Snitch was used during the speeder chase scene in Star Wars: Episode II - Attack of the Clones (2002). John Williams did both scores.

Robbie Coltrane had to turn down a part on The West Wing (1999) to reprise his role as Hagrid.

Many Harry Potter fans went to see Scooby-Doo (2002) just to see a trailer for this movie.

Chris Columbus wanted the movement of the camera to be snake-like, reflecting the basilisk's movement throughout the castle. Hence, certain scenes were filmed using hand-held cameras, which allowed for more fluid camera movement, and Columbus at one point, actually steered the camera operator (by holding him by the shoulders), in order to get the shots exactly where he wanted them.

Daniel Radcliffe has said that "Harry Potter and the Chamber of Secrets" is his favorite book.

On an episode of Have I Got News for You (1990) broadcast around this movie's release, the panelists discuss an article claiming that the Russian President (later Premier) Vladimir Putin was deeply disturbed and offended that Dobby the house-elf seemed to have been created in his image. There is an undeniable resemblance either way.

(At around thirty-three minutes) Although the subplot which involved Percy Weasley and Penelope Clearwater (when Ginny discovered them kissing, and promised not to tell anybody) was cut, while Nearly Headless Nick is on his way to the Great Hall, he does say "Hello Percy, Ms. Clearwater" to the couple as they walk out.

(At around eleven minutes) In order to create a realistic image of the floating set of needles knitting in the Burrow, one of the crew coerced his mother to let them film her for several hours as she did her own knitting.

To get a sense of how nasty his character should be, Jason Isaacs had to go back and watch Tom Felton's performance in Harry Potter and the Sorcerer's/Philosopher's Stone (2001).

The filmmakers assumed that the Chamber of Secrets' only appearance would be in this movie. However, the Chamber ends up making a second appearance in Harry Potter and the Deathly Hallows: Part 2 (2011). Since the set had been dismantled, it had to be constructed again.

Jude Law was deemed too young to play Gilderoy Lockhart, but played a young Albus Dumbledore in Fantastic Beasts: The Crimes of Grindelwald (2018).

All four of Chris Columbus' children appear in this movie. Eleanor Columbus plays Susan Bones (she also played her in the first movie), Brendan Columbus played a boy in study hall, Violet Columbus played the little girl with flowers, and Isabella Columbus played the little girl in the bookstore.

A theater manager in Stavanger, Norway reported that the movie was making his younger patrons ill. Evidently, many children who had overindulged on sweets and popcorn were throwing up when Ron begins vomiting giant slugs. "It is not a particularly fun task for our employees to have to wash away the sick", he said.

Jason Isaacs provided the voice of the basilisk calling to its victims. Chris Columbus thought Isaacs was so good at doing voice-over work, he asked him to create a creepy sounding voice for the basilisk, considering the book only describes it as a hissing sound.

The tapestries hanging in the Gryffindor Common Room are copies of the "Lady and the Unicorn" series, a set of sixteenth century tapestries, that are now displayed in the Cluny Museum in Paris.

The film earned over $88 million in the U.S. on its opening weekend, which at the time placed it third in the list of all-time biggest openings, behind Spider-Man (2002) and Harry Potter and the Sorcerer's/Philosopher's Stone (2001).

(At around one hour and nineteen minutes) During the filming of the scene where Crabbe and Goyle eat the floating cupcakes, Jamie Waylett and Josh Herdman cut their mouths on the hooks which were used to attach the cupcakes to the fishing line that was holding them up.

(At around twenty-one minutes) In a bit of foreshadowing, that is only seen in the movie version, Lucius Malfoy takes one book out of Ginny Weasley's cauldron, but drops two back in.

Richard E. Grant and Bill Nighy were considered for the role of Lucius Malfoy. The latter would later sign on to Harry Potter and the Deathly Hallows: Part 1 (2010), for the role of Minister Rufus Scrimgeour.

One of two Harry Potter movies not to be nominated for an Academy Award, the other being Harry Potter and the Order of the Phoenix (2007).

During the shoot, the part of Dobby was played by a ball on a stick (he was added digitally later, of course).

Harry used Arania Exumai, a stunning or killing spell for use against spiders, while attempting to escape the Acromantula colony. He learned the spell from Tom Riddle upon visiting the latter's sixteen-year-old memory in his diary. The spell was never mentioned in the book.

Some of the portraits in Hogwarts are faces of Stuart Craig and executive producer Mark Radcliffe.

The various bookcases and cabinets in Dumbledore's office actually concealed removable walls (known in the movie industry as "wild walls") that allowed the cameras to have enough room to be able to shoot from various angles, as the set, despite its grandiose appearance, was rather cramped.

In recalling his father reading the first two Harry Potter books to him, Daniel Radcliffe stated that his father had a great voice for the Basilisk. He suggested his father to director Chris Columbus and his father was mortified.

Jason Isaacs originally auditioned for Gilderoy Lockhart, but Chris Columbus asked him to try for Lucius Malfoy too. Isaacs didn't want to, because it was too similar to his role as Captain Hook in Peter Pan (2003) , but was too polite to say no. When he was offered the part, Isaacs almost turned it down, but family members convinced him to do it.

The set for Flourish and Blotts is a redress of the set that served as Olivander's Wand Shop in Harry Potter and the Sorcerer's/Philosopher's Stone (2001).

Due to scheduling conflicts, John Williams was not able to deliver a fully elaborated score. Composer William Ross was hired to adapt Williams' material, to complete the score, and was subsequently conducting the orchestra during the recording sessions.

(At around one hour and twenty-eight minutes) When Harry speaks to Tom Riddle by writing in the diary, the handwriting seen isn't that of Daniel Radcliffe. Chris Columbus didn't feel that Radcliffe's handwriting was how Harry would write, so an extra's handwriting was used instead.

(At around one hour and five minutes) The salute that Snape, Lockhart, Harry, and Draco make during their Dueling Club session is a modified version of the salute made in fencing.

Tickets for this movie went on sale in Britain more than a month before it was due to open.

The character of Mr. Borgin, played by Edward Tudor-Pole, was cut from the final movie. The scenes were later included as a bonus feature on the DVD.

(At around one hour and twenty-one minutes) In the book, the Polyjuice Potion changes a person completely, including his or her voice. You will notice that there was no change in Mad-Eye Moody's voice in Harry Potter and the Goblet of Fire (2005). Harry and Ron do not have to disguise their voices when they confront Malfoy, but instead have to be careful about the way that they talk, in order to sell their identities of Crabbe and Goyle so that Malfoy doesn't suspect anything.

While writing "Deathly Hallows", J.K. Rowling was seriously considering bringing the Ford Anglia back to defend Ron from a pair of Death Eaters that corner him on the castle grounds. The car was to emerge from the forest and run the Death Eaters straight into a wall of the castle, the car's lights then gave out slowly as if it died. But she opted out of it, as she thought the Ford Anglia would most likely have been destroyed due to living in the forest for too long, and the idea itself seemed childish to her.

The title used by the crew to disguise the shoot (and printed on the clapper boards) was "Incident on 57th Street", the title of a 1973 Bruce Springsteen song.

Chris Columbus was unsure about Jason Isaacs' ideas for Lucius Malfoy's costume, hair, and voice. It was Daniel Radcliffe who commented that he thought the changes were "really cool", and Columbus went along with it.

In his appearance on 8 Out of 10 Cats (2005), Alan Cumming revealed that he had been offered the role of Gilderoy Lockhart in this movie, but when he learned from his agent how much more money Rupert Grint, with whom he shares an agent, would be getting paid, he refused to sign on, as he would not agree to be paid less than "a twelve-year-old amateur!"

Bonnie Wright revealed that she filmed a scene in which Ginny strangles roosters outside of Hagrid's hut. In the book, it was revealed that Ginny, under Tom Riddle's influence, killed Hagrid's roosters, since the crow of roosters is fatal to the basilisk. This fact is entirely omitted from the movie, therefore the scene was cut.

The train station interior used in this movie is King's Cross in North London, whereas the exterior shot is actually St. Pancras. The two stations are adjacent to one another, but not the same building. This was done because the architecture of St. Pancras is much more visually appealing.

(At around one hour and thirteen minutes) The spell to open Dumbledore's office is Sherbet Lemon. That is a hint to the first book, where Dumbledore admits that he grew quite addicted to sherbet lemons.

In the book, it is Professor Binns who explains the origins of the Chamber of Secrets, not Professor McGonagall.

Dobby's ears were based on an art department dog named Max that used to sit under the designers' desks.

Madam Pomfrey only appeared in the background of Harry Potter and the Sorcerer's/Philosopher's Stone (2001), played by an extra. Here, Gemma Jones assumes the role, and keeps it for the remainder of the franchise.

In order to prevent damage to the five-hundred-year-old building, a false wall was erected at Gloucester Cathedral for the scene in which Harry and his friends discover the message from the Heir of Slytherin written on the wall.

In the book series, the forest outside Hogwarts is called the Forbidden Forest. In the first two movies, it is called the Dark Forest. In Harry Potter and the Deathly Hallows: Part 2 (2011), Voldemort calls it the Forbidden Forest.

One of Chris Columbus' daughters had trouble reading, until she read Harry Potter and the Sorcerer's/Philosopher's Stone in two days, which opened her eyes to the world of books. After reading The Chamber of Secrets, she asked her dad to make movies out of them, but there were fifty other directors already interested. Columbus fell in love with the first two books as well.

The camera used by Colin Creevey is an Argus C3 Matchmatic, a cheap, and very popular, 35mm rangefinder camera manufactured in the U.S. from 1939 to 1966.

Sally Mortemore was cut from the movie as Hogwarts Librarian Madam Irma Pince. She only appears in the background and briefly at the staff table during dinner scenes.

The film cast includes one Oscar winner: Dame Maggie Smith; and four Oscar nominees: Richard Harris, Sir Kenneth Branagh, Dame Julie Walters, and John Cleese.

Despite the fact that Crabbe and Goyle have more screentime in this movie than any of the others, they have no dialogue, as their voices were dubbed over by Daniel Radcliffe and Rupert Grint for the Polyjuice Potion sequence.

The first name of the character of Salazar Slytherin is based on the former Portuguese dictator Salazar, as it was in Portugal, and namely the city of Oporto, where J.K. Rowling had the idea and wrote her favorite parts of the first Harry Potter book.

Harry Potter and the Sorcerer's/Philosopher's Stone (2001) and this movie are Chris Columbus' two biggest financial hits.

Chris Columbus was amazed how beautifully Daniel Radcliffe, Emma Watson, and Rupert Grint matured over the Harry Potter franchise, compared to some child actors and actresses who start out adorable, and then either lose that or become bad actors and actresses as they grow older.

There is a discrepancy in the description of the size of the basilisk between the novel and movie versions, with the snake being implicitly described as being much larger in the latter. At the end of chapter 16 of the novel, when Harry, Ron, and Lockhart find the snakeskin in the novel, the narration states that "the creature that had shed it must have been twenty feet long at least." In the corresponding scene in the movie, Ron states "whatever shed this must be sixty feet long, or more."

Chris Columbus has a figure of Dobby the Elf in his office.

When Ginny Weasley stands up for Harry when Malfoy taunts him, Malfoy jokes Harry has a girlfriend. Coincidentally, this foreshadows the Half-Blood Prince, as Harry and Ginny do become a couple.

The guard that confronts Harry and Ron when they fail to get to platform nine and three quarters was the same guard from Harry Potter and the Sorcerer's/Philosopher's Stone (2001).

A story circulated, that Emma Watson broke her left wrist during filming, and that you can just see a little bit of the cast under her sleeve in some scenes, but it turned out to be false.

Aragog was falsely accused by Tom Riddle for the Petrification of many students before the death of Moaning Myrtle. Acromantula are not known to be able to induce petrification, marking this as another lack of insight of the justice system of the Ministry of Magic, as they fail to notice the discrepancy.

Through advance ticket sales at Odeon Cinemas, this movie generated more than £1 million (roughly two hundred thousand tickets) before its release in the U.K. An additional £8 million was generated through preview showings at U.K. cinemas (both Odeon and non-Odeon).

The animatronic puppet of Aragog can be found on display at "The Making Of Harry Potter" studio tour in Leavesden.

It has been theorized that spiders fear basilisks because arachnids can see 360-degrees around them and cannot shut their eyes, leaving them extremely vulnerable to the monster's killing gaze, although this theory does not explain why frogs and dragonflies do not fear the basilisk, as they have an even greater field of vision.

In 2017, in celebration of the 20th Anniversary of "Harry Potter" franchise, arachnologists Anton A. Nadolny and Alireza Zamani named a new species of Iranian wolf spiders (Lycosidae) after Aragog, as Lycosa aragogi. The single specimen was collected on April 26, 2016, almost nineteen years to the day after Aragog died (April 20, 1997 in the world of the book), according to the "Harry Potter" series, by J.K. Rowling.

Because John Williams had a very tight schedule, the music in several scenes is temp-tracked from Harry Potter and the Sorcerer's/Philosopher's Stone (2001).

Shirley Henderson (Moaning Myrtle) (a ghost who consistently cries in the girl's lavatory) also is first shown crying in a ladies restroom in another popular movie, Bridget Jones' Diary (2001). Her character in Bridget Jones' Diary (2001) is very similar to Moaning Myrtle, as Bridget says she spends most of her time crying in the ladies room, crying about her boyfriend rather than doing her job.

The Acromantulas more closely resemble wolf spiders (family Lycosidae) than actual tarantulas (family Theraphosidae), but that may reflect upon the fact that wolf spiders were the first kind of spider to ever be referred to as "tarantulas".

(At around one hour and twenty-nine minutes) When Tom Riddle sucks Harry into his diary, taking him back fifty years, the date is June 13. This is a clever insertion, as from the point in time when this happens in Harry's second year, dating it back fifty years to June 13, was in fact, a Friday.

Sir Kenneth Branagh (Professor Gilderoy Lockhart), Robert Hardy (Cornelius Fudge), and John Cleese (Nearly Headless Nick) appeared in Mary Shelley's Frankenstein (1994), which Branagh also directed.

This was the second of two (uncredited) appearances for Katherine Nicholson as Pansy Parkinson, in Harry Potter and the Sorcerer's/Philosopher's Stone (2001), and this movie. She was the first of five actresses to play the role.

According to Harry Potter: The Creature Vault, Aragog "was such a beloved character that the design crew wore black armbands while the spider's final scene (Aragog's funeral) was filmed" during Harry Potter and the Half-Blood Prince (2009).

Aragog could possibly have been inspired by Shelob from the novel "The Lord of the Rings".

Joseph Morgan auditioned for the role of Tom Marvolo Riddle.

Wearing glasses will not protect a person from the fatal effect of the basilisk's stare, because glasses still allow one's line of vision to connect directly and clearly with the serpent's eyes, unlike looking in a mirror or through a camera. This is why Moaning Myrtle died, the reason Harry was safe is cause Fawks blinded it.

The Acromantulas refusing to speak of the Basilisk, is similar to the witches and wizards who refuse to say Voldemort's name, instead referring to him as "He Who Must Not Be Named" or "You Know Who".

Various medias have shown both the male and female depictions of the species for Slytherin's Basilisk. In the book, it seemed to be female: when Harry first saw it, he described it as "vivid, poisonous green", but made no mention of a red crown, which implied that either it had one and he simply didn't see it, or that the Basilisk was female, that was further supported by Pottermore, which depicted the Basilisk with a distinct lack of a crown, red or otherwise. Though the voice Harry "hears" in the movie sounds male, the Basilisk in the movie likewise seems to lack a distinctive crown on its head.

In this movie, Filch sits outside the Great Hall and waits for Harry and Ron to show up after they arrive by car. This similarly happened in the book version of Harry Potter and the Sorcerer's/Philosopher's Stone, where Filch caught Harry and Hermione after they helped Hagrid dispose of Norbert and even says the same line that they are in trouble. The only difference is that Ron is in trouble in this movie.

(At around twenty-one minutes) Lucius Malfoy slipped Tom Riddle's diary into Ginny Weasley's cauldron, in the book shop, after demeaning her for her secondhand book. It is behind the book he first took out of the cauldron.

Although Chris Columbus returned to direct, Frank Oz said in an interview with The A.V. Club that he was asked to direct this movie, but he had no interest in it.

Chris Columbus sold Steven Spielberg the scripts for Gremlins (1984) and The Goonies (1985), but his career didn't fully take off until the massive successes of Home Alone (1990) and Mrs. Doubtfire (1993), which led to the even greater success of the Harry Potter film franchise.

Fiona Shaw, who portrayed a woman despising the supernatural and witchcraft in this movie, portrayed a powerful witch in True Blood (2008).

This is Toby Jones' first voice-over movie. His next one was Christopher Robin (2018).

At the beginning of the movie, Harry is looking through the photo album he'd received from Hagrid at the end of Harry Potter and the Sorcerer's/Philosopher's Stone (2001). The first photo he sees is of his parents, James (Adrian Rawlins) and Lily (Geraldine Somerville), holding Baby Harry (Saunders Triplets). None of them were credited.

When Chris Columbus scripted Young Sherlock Holmes (1985), Watson believed Holmes obsessed over a case, because unlike other boys his age, even at Christmas, he had no family to which to go home, like Harry Potter or Kevin McCallister, and Columbus has ties to both the Harry Potter and Home Alone film franchises.

The Weasleys' car registration number is 7990 TD. This is a genuine registration for a blue Ford, first issued in April 1960.

Throughout the eight-movie franchise, five actresses played "Pansy Parkinson": 1. Katherine Nicholson (Harry Potter and the Sorcerer's/Philosopher's Stone (2001), and this movie, uncredited in both). 2. Genevieve Gaunt (Harry Potter and the Prisoner of Azkaban (2004)). 3. Charlotte Ritchie (Harry Potter and the Goblet of Fire (2005), originally listed as "Student", and uncredited)). 4. Lauren Shotton (Harry Potter and the Order of the Phoenix (2007), uncredited again as Pansy. 5. Scarlett Byrne in Harry Potter and the Half-Blood Prince (2009), Harry Potter and the Deathly Hallows: Part 1 (2010), and Harry Potter and the Deathly Hallows: Part 2 (2011).

This is the second time and the second movie Harry and Ron get detention. Harry receives detention two more times in Harry Potter and the Order of the Phoenix (2007) under Umbridge for telling "lies" and teaching "Dumbledore's Army". Ron and Hermione get detention for the third and second time, respectively, in the latter movie for being part of "Dumbledore's Army".

Just after Dobby causes the pudding to fall on top of Mrs. Mason, a picture of a young boy with blonde hair can be seen on a table next to Harry. The boy in the picture strongly resembles Kevin McCallister, who is the main character in the first two Home Alone movies. Director Chris Columbus also directed the first two Home Alone movies.

Caio Cesar, a prominent Brazilian voice actor who dubbed Daniel Radcliffe as Harry Potter, and in other movies, was also a military cop and died at the age of 27 in 2015 after being shot at the Complexo do Alemão slums in Rio de Janeiro.

Since they say that is has been 50 years since the chamber has been opened, and both Haggrid and Voldermort were there when it was opened, it can be guessed that Tom is around 66 years of age, and Hagrid is 63 during this movie.

Kate Duchêne, who plays Miss Hardbroom on the television series The Worst Witch (1998), was reportedly offered a role in the movie, but supposedly declined.

In the trailer, it shows Harry in the Chamber of Secrets, but not once does it show the complete head of Salazar Slytherin, nor the basilisk.

In Armageddon (1998), Harry Stanton (Bruce Willis) sarcastically called Dr. Ronald Quincy (Jason Isaacs) "Mr. Wizard". Four years later, Isaacs began portraying wizard Lucius Malfoy.

In the novel, Aragog is blind as his eyes were milky white. In this movie, his eyes are black, implying he can see.

The tone of the movie getting darker and edgier was already referenced in the main title, where, after the crescendo in "Hedwig's Theme" during the approach of the Warner Brothers logo, as the Harry Potter logo is revealed, the theme reaches a brand new, quieter arrangement, that is quite foreboding and ominous compared to the existing arrangements from Harry Potter and the Sorcerer's/Philosopher's Stone (2001). The "and the Chamber of Secrets" subtitle is also revealed at the moment the bass strings enter.

There are thirty-five minutes in the second half of this movie in which Hermione does not appear, after being petrified.

Harry, Ron, and Hermione are discussing how they can use Polyjuice Potion to impersonate Crabbe and Goyle (which will allow them to get information out of Draco). They are doing this in order to find out if Draco is the Heir of Slytherin. Afterwards, Hermione goes to the library and gets a book called "Most Potente Potions". To the right of the book she is reaching for is another book with only the word "TOM" written on the spine. Why do they need to make Polyjuice Potion? To find out if Malfoy is the Heir of Slytherin. Who is the true Heir of Slytherin? Lord Voldemort, also known as Tom Riddle. Bonus point: The book with "TOM" on the spine is the second book to the right of the one Hermione is getting, and Voldemort considers Tom Riddle to be his secondary, lesser identity since he became Voldemort. Voldemort's theme from Harry Potter and the Sorcerer's/Philosopher's Stone (2001) plays at various points in the movie, foreshadowing his involvement.

The second of eight movies based on the Harry Potter book series by J.K. Rowling.

The Harry Potter film franchise, and Young Sherlock Holmes (1985), which was scripted by Chris Columbus, share many similarities.

Shirley Henderson (Moaning Myrtle) and Matthew Lewis (Neville Longbottom) appeared in Happy Valley (2014).

Lucius' and Harry's exchange just before Lucius leaves Dumbledore's office was not in the script, but completely improvised by the actors on the spot. Jason Isaacs thought he should say something and Chris Columbus told him to try something. Isaacs quipped "Let us hope that Mr. Potter will always be around to save the day" and Daniel Radcliffe immediately replied "Don't worry, I will be". This ended up both in the final cut of the film and the trailer.

When Harry is in the basement of the shop, his hand is caught in a creepy hand. In Mary Shelley's Frankenstein (1994), Sir Kenneth Branagh puts an electric charge through a monkey's hand that grabs his friend Tom Hulce's hand. Sir Kenneth Branagh plays Gilderoy Lockheart in this movie.

(At around two hours and five minutes) Foreign language translations had to change Tom Marvolo Riddle's name, so that an appropriate anagram could be formed: In Spanish, his name became "Tom Sorvolo Ryddle", which transforms into "Soy Lord Voldemort". In French, his name is "Tom Elvis Jedusor", which becomes "Je suis Voldemort". In Dutch, his name is "Marten Asmodom Vilijn", which is an anagram for "Mijn naam is Voldemort". In Turkish, the name is "Tom Marvoldo Riddle", which makes up "Adim Lord Voldemort". In Brazilian Portuguese, the name is "Tom Servolo Riddle", which makes up "Eis Lord Voldemort". In Danish, his name is "Romeo G. Detlev, Jr.", which makes up "Jeg er Voldemort". In Italian, his name is "Tom Orvoloson Riddle", which makes up "Son io Lord Voldemort". In German, his name is "Tom Vorlost Riddle", which makes up "Ist Lord Voldemort". In Icelandic, his name is "Trevor Délgome", which makes up "Ég er Voldemort". In Swedish, his name is "Tom Gus Mervolo Dolder", which makes up "Ego sum Lord Voldemort" (which is actually in Latin).